Chris Chatham
developingintelligence
Posts by this author
January 3, 2008
Over New Year's I had a brief discussion with a condensed-matter physicist who proclaimed that 1) "some developmental research is amazingly bad" and that 2) "they think they can tell what a baby has learned from what direction it looks," topping it all off with 3) "you guys don't even know what…
January 2, 2008
Play is more often simply observed than studied scientifically - play behaviors occur unpredictably and, when they do occur, are highly chaotic, making it very difficult to study them in the laboratory. Despite these challenges, new work is beginning to make play accessible from a rigorous…
December 31, 2007
Originally posted on 12/16 2006:
The term "executive function" is frequently used but infrequently defined. In attempting to experimentally define executive functions in terms of their relationship to age, reasoning and perceptual speed, Timothy Salthouse reviewed the variety of verbal definitions…
December 13, 2007
If you encounter a difficult situation, you may be extra careful afterwards, even in a different or unrelated situation. This intuitive statement has recently been confirmed in a laboratory task, and extended to show that such carry-over "conflict adaptation" effects may affect the speed with…
Dispute Over the Canonical Cortical Circuit: Structure-Function Dissociations in the Cortical Column
December 10, 2007
Is there a basic "computational unit" of the neocortex? In contrast to subcortical regions, neocortical architecture seems fairly regular and matrix-like - leading to it's other name, "isocortex." While there are many contenders for the title of the "canonical circuit" or "cortical algorithm",…
December 4, 2007
How does memory help to accomplish moment-to-moment goal-directed action? Classic accounts, such as Baddeley's working memory model, suggest that there are separate storage and processing ("executive") mechanisms, whereas newer accounts (proposed by a variety of researchers) propose that storage…
December 3, 2007
Your IQ can be reliably predicted by simple reaction time tasks - perhaps even more reliably than with much more complex cognitive tasks. This surprising psychometric fact has led to the belief in human "processing speed." In the same way that a computer with a faster microprocessor might carry…
November 30, 2007
A lot of good brain blogging lately; some beautiful drawings from the era of phrenology, some crazy kids high on scopolamine, James Flynn's current thoughts on intelligence, and more...
Who has better graphics? It's a close call between the phrenology of old and today's fMRI.
Beware the No2 Pencil…
November 29, 2007
The world wide web can be understood as a giant matrix of associations (links) between various nodes (web pages). At an abstract level, this is similar to human memory, consisting of a matrix of associations (learned relationships, or neuronal connections) between various nodes (memories, or the…
November 29, 2007
The ability to actively maintain more information in memory, known as "working memory," seems to benefit performance in a variety of tasks. One idea is that these tasks require controlled attention, allowing for better control over behavior.
But there's a serious problem with this explanation:…
November 19, 2007
Geoff Hinton has a new TiCS paper describing recent advances in algorithms used to train multilayered neural networks.
First, a little background: neural networks of a sufficient size can calculate any mathematical function (an infamous proof among neural network modelers). Unfortunately, the…
November 16, 2007
Neuroesthetics seeks to identify the neural basis of aesthetic experience - how does the brain give rise to the perception of beauty? A new paper in Network indicates that artists consistently create works which contain the same statistical properties as natural scenes, even when the objects being…
November 9, 2007
Asperger's disorder is a subtype of autism, characterized by deficits in social interaction, delays in nonverbal communication and possibly also deficits in nonverbal IQ (such as on a test known as Block Design). However, a new study in Brain and Cognition challenges this latter claim - with…
November 7, 2007
Speech recognition remains a daunting challenge for computer programmers partly because the continuous speech stream is highly under-determined. For example take coarticulation, which refers to the fact that the auditory frequencies corresponding to a given letter are strongly influenced by the…
November 5, 2007
Aging is associated with some slow but measurable forms of cognitive decline, but there is debate over the type of cognitive changes taking place. A recent study by Rush, Barch & Braver uses a series of interesting tasks to clarify the nature of this cognitive decline. The results seem to…
November 4, 2007
A first-hand report of caloric vestibular stimulation - to treat Body Integrity Identity Disorder, in which patients often desire to have large parts of their bodies amputated.
Ambien, a sleep drug recently discovered to awaken some people from comas is also linked to strange behavior: one woman…
November 2, 2007
Trueswell & Kim's paper in the Journal of Memory and Language describes a phenomenon known as "fast priming," in which a reading task is momentarily interrupted by a brief presentation of a "prime" word, usually lasting around 30 to 40 ms. The reading task then continues, and although subjects…
November 1, 2007
When one object passes in front of another we know that the occluded object has not vanished, and yet representations in our visual cortex have been assumed not to reflect this information. Instead, such "object permanence" information has been thought to require active maintenance, perhaps with…
October 31, 2007
Several high-profile studies have shown that bilingual children outperform their monolingual peers in terms of several cognitive abilities - including tests of verbal and nonverbal problem-solving, selective attention, flexibility (e.g., task-switching) and others. These studies have captured the…
October 30, 2007
Synaesthesia involves the inappropriate binding of one perception to another - for example, color-grapheme synaesthetes might perceive the letter "h" to be noticeably red, and are actually slower to identify the letter "h" when it is green than when it is red or gray. This "inappropriate binding"…
October 29, 2007
One of the more surprising findings to emerge from the intelligence literature is that an individual's ability to think in highly complex and abstract forms is related to speed in tasks as simple as "press the lighted button." Simple reaction time tasks like this have amazing predictive power for…
October 17, 2007
Several have criticized my post on handedness by pointing to evidence (or hearsay) that animals do have handedness. This evidence comes in several forms:
Anecdote: "My cat plays with its right paw"
Individual or Activity-Specific Cases: "Horses reliably pick one leg to lead their galloping" or "…
October 17, 2007
Cortical Column is a new blog by computational modeler and volleyball freak Brian Mingus - check out the interesting posts on "The Simulation Argument" and Deep Pressure Stimulation, which is argued to simulate deep brain stimulation of intralaminar thalamic nuclei - noninvasively!
October 16, 2007
Although most humans are right-handed, other animals don't seem to show a similar motoric asymmetry. As Corballis mentions in his 2003 BBS article, even the great apes - our closest relatives in the animal kingdom - tend not to show a right-hand preference unless raised in captivity, suggesting…
October 3, 2007
Ambiguity is a constant problem for any embodied cognitive agent with limited resources. Decisions need to be made, and their consequences understood, despite the probabilistic veil of uncertainty enveloping everything from sensory input to action execution. Clearly, there must be mechanisms for…
October 2, 2007
Children are often thought to be imaginative and fanciful, not only in their perception of the world but also in the veridicality of their memories. It may therefore be surprising that a robust method for eliciting false memories in adults is actually ineffective in children. In fact, children…
September 27, 2007
Cognitive scientists are increasingly aware of how individual differences can confound experimental results. That is, differences in group means cannot always be interpreted clearly if, for example, only some subset of individuals in each group demonstrates the effect. Consequently, even the…
September 26, 2007
Infantile "amnesia" refers to the apparent absence or weakness of memories formed at ages younger than 3 or 4. Some evidence indicates that these early-life memories are not actually lost or forgotten, but are rather merely mislabeled or otherwise inaccessible to adult cognition. One potential…
September 25, 2007
Say you are writing an email when the phone rings. After the phone call, you return to finish the email. Are you slower to continue writing this email than you would be if you'd been doing something else prior to the phone call? In general, yes - at least according to the finding known as lag-2…
September 24, 2007
What processes allow us to execute delayed intentions? This ability, known as prospective memory, is often considered to have two constituent parts: a prospective component which involves forming the intention and possibly maintaining it until action execution, and a retrospective component which…